Hello everyone! Excited to start a new project on a 1950 Chevy 3100. This truck is my wife's grandpa's that he bought for $100 off a farmer in 1970. My mother-in-law wants to restore it for him and I don't start work until September so I will be working on it for the next 3 months. The overall shape of the truck is great, it has been sitting in a driveway and we were able to shift to neutral, steer it out, and only have to remove one drum to get the wheel to turn. I had a few things I was hoping to get advice on.
1) the engine (216 I6) has been sitting for 30 years with no valve covers and the rockers are rusted. I'm afraid it is seized and we will need to replace it. What are the most common swaps that someone new to this can do without much modification?
2) Who has the best supply of parts for these? I found lmctruck.com but they don't have a few things like drum brake rebuild kits, etc..

Thanks in advance for the advice!